Editing Atlantic cod (section)

==Feeding and diet==
The diet of the Atlantic cod consists of fish such as [[Clupea|herring]], [[capelin]] (in the Eastern Atlantic Ocean), and [[sand eel]]s, as well as [[Mollusca|mollusks]], [[tunicate]]s, [[Ctenophora|comb jellies]], [[crustacean]]s, [[echinoderm]]s and [[Marine worm|sea worms]].<ref>{{cite web | url=https://animaldiversity.org/accounts/Gadus_morhua/ | title=Gadus morhua (Cod) | website=[[Animal Diversity Web]] }}</ref> Stomach sampling studies have discovered that small Atlantic cod feed primarily on crustaceans, while large Atlantic cod feed primarily on fish.<ref name=Daan>{{cite journal|last=Daan|first=N.|title=A quantitative analysis of the food intake of North Sea cod, Gadus Morhua|journal=Netherlands Journal of Sea Research|date=1 December 1973|volume=6|issue=4|pages=479–517|doi=10.1016/0077-7579(73)90002-1|bibcode=1973NJSR....6..479D}}</ref>  In certain regions, the main food source is [[decapods]] with fish as a complementary food item in the diet.<ref name=Klemetsen>{{cite journal|last=Klemetsen|first=A.|title=Food and feeding habits of cod from the Balsfjord, northern Norway during a one-year period|journal=ICES Journal of Marine Science|date=1 May 1982|volume=40|issue=2|pages=101–111|doi=10.1093/icesjms/40.2.101}}</ref> Wild Atlantic cod throughout the [[North Sea]] depend, to a large extent, on commercial fish species also used in fisheries, such as [[Atlantic mackerel]], [[haddock]], [[Merlangius|whiting]], [[Atlantic herring]], [[European plaice]], and [[common sole]], making fishery manipulation of cod significantly easier.<ref name=Daan /> Ultimately, food selection by cod is affected by the food item size relative to their own size. However, providing for size, cod do exhibit food preference and are not simply driven by availability.<ref name=Daan />

Atlantic cod practice some [[cannibalism (zoology)|cannibalism]]. In the southern North Sea, 1–2% (by weight) of stomach contents for cod larger than {{cvt|10|cm|in|0}} consisted of juvenile cod. In the northern North Sea, cannibalism was higher, at 10%.<ref name=Daan /> Other reports of cannibalism have estimated as high as 56% of the diet consists of juvenile cod.<ref name="Ponomarenko 1965 349–354">{{cite journal|last=Ponomarenko|first=I. Ja|title=Comparative characteristics of some biological indices of the bottom stages of 0-group cod belonging to the 1956, 1958, 1959, 1960 and 1961 year-classes|journal=Spec. Publ. Int. Comm. Northw. Atlant. Fish|year=1965|pages=349–354}}</ref>

When hatched, cod larvae are [[Precociality and altriciality|altricial]], entirely dependent on a yolk sac for sustenance until mouth opening at ~24 degree days.<ref name=":4">{{Cite journal |last1=Perez-Casanova |first1=J.C. |last2=Murray |first2=H.M. |last3=Gallant |first3=J.W. |last4=Ross |first4=N.W. |last5=Douglas |first5=S.E. |last6=Johnson |first6=S.C. |date=February 2006 |title=Development of the digestive capacity in larvae of haddock (Melanogrammus aeglefinus) and Atlantic cod (Gadus morhua) |url=https://linkinghub.elsevier.com/retrieve/pii/S0044848605003789 |journal=Aquaculture |language=en |volume=251 |issue=2–4 |pages=377–401 |doi=10.1016/j.aquaculture.2005.06.007|bibcode=2006Aquac.251..377P }}</ref> The stomach generally develops at around 240 degree days.<ref name=":4" /> Before this point the intestine is the main point of food digestion using pancreatic enzymes such as trypsin.<ref name=":4" />